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A J Hibbard

Publications and source records attributed to A J Hibbard.

4 recordsLinked to original sources
PubMed2003

Serological responses to Cryptosporidium antigens among users of surface- vs. ground-water sources.

Cryptosporidium oocysts are commonly detected in surface-derived drinking water. However, the public health significance of these findings is unclear. This study compared serological responses to two Cryptosporidium antigen groups for blood donors and college students using chlorinated and filtered river water vs. ground-water sources. The surface water received agricultural and domestic sewage discharges upstream. Participants from the surface-water city had a higher relative prevalence (RP) of a serological response to the 15/17-kDa antigen group (72.3 vs. 52.4%, RP = 1.36, P < 0.001) and to the 27-kDa antigen group (82.6 vs. 72.5%, RP = 1.14, P < 0.02). Multivariate logistic regression analysis found that the people with a shorter duration of residence or drinking bottled water also had a lower seropositivity for each marker. Use of private wells was associated with a higher prevalence of response to the 15/17-kDa markers. Seroconversion to the 15/17-kDa antigen group was more common in the residents of the city using surface water. These findings are consistent with an increased risk of Cryptosporidium infection for users of surface-derived drinking water compared with users of municipal ground-water-derived drinking water. Users of private well water may also have an increased risk of infection.

Adult↗
PubMed1992

Multiple false-positive serologic tests for HIV, HTLV-1, and hepatitis C following influenza vaccination, 1991.

OBJECTIVE: (1) To assess factors associated with the occurrence of multiple false-positive viral enzyme-linked immunosorbent assays (ELISAs) for human immunodeficiency virus (HIV), human T-cell lymphotrophic virus type 1 (HTLV-1), and hepatitis C virus (HCV) among individual blood donors and (2) to determine the frequency and time course of this phenomenon. DESIGN: Case-control study. SETTING: A regional blood center. PARTICIPANTS: Blood donors found to have multiple false-positive viral ELISAs (case donors) and randomly selected seronegative controls (control donors) who donated between October 31, 1991, and December 15, 1991. An additional random sample of 262 donation records was reviewed to calculate the proportion of donors who received influenza vaccine. MAIN OUTCOME MEASURES: Multiple false-positive viral ELISAs, receipt of influenza vaccination formulated for the 1991-1992 influenza season, and follow-up ELISA results on serum samples obtained from case donors. RESULTS: Among 17,941 donors, 10 case donors were identified. Nine of the 10 case donors received influenza vaccine, compared with three of 30 control donors (odds ratio [OR] = 81; 95% confidence interval [CI], 6 to 3670; P less than .001). Among nine case donors, the mean time between vaccination and blood donation was 26 days (range, 9 to 68 days). Follow-up ELISAs of serum samples from seven case donors obtained 52 to 130 days (mean, 75 days) after vaccination demonstrated reversion to HIV and HTLV-1 seronegativity in all but one specimen, with persistence of positive HCV ELISAs in four specimens. We estimate between 0.6% and 1.7% of blood donors who received influenza vaccine this season had multiple false-positive viral ELISAs. CONCLUSIONS: The occurrence of multiple false-positive viral ELISAs among blood donors was associated with influenza vaccination, but was infrequent among vaccinees. This phenomenon is of short duration for HIV and HTLV-1, but may persist longer for HCV. We recommend influenza vaccinees not be deferred from blood donation. Blood donors with multiple false-positive viral ELISAs should be considered for future reentry as blood donors.

Adult↗
PubMed1985

Laryngeal injury in a dog model of prolonged endotracheal intubation.

Using a dog model of prolonged translaryngeal intubation, the authors studied laryngeal injury. Segments of 10.7 mm diameter endotracheal tube were sutured in place in the larynges of anesthetized animals, and the animals were allowed to awaken and the tubes left in place for periods of 24 h to 84 days in a total of 13 dogs. Each animal's larynx was studied endoscopically at weekly intervals and at the time of death. Both endoscopic and postmortem examination revealed erythematous laryngeal mucosa at 24 h and severe mucosal ulceration by 1 week. Microscopic examination revealed mucosal inflammation at 24 h with loss of mucosal architecture by 1 week. In several animals intubated 1 week or longer, inflammatory infiltrates were present in the arytenoid cartilage. While damage was generally severe by 1 week, it did not tend to become more severe after that time. Between week 1 and week 12, there was no significant correlation of the severity of laryngeal injury with the duration of endotracheal intubation. The results suggest that duration alone may not be a factor in laryngeal injury after the first week of intubation.

Animals↗